Just read your thread; ugh, this sounds really, really hard. I am sorry to read all this. It must be terribly painful! He is moving at lightening speed, has essentially abandoned his step-son, and is now pressuring you to take what money he offers you. Yikes, this guy is a bit off his rocker, isn't he! I am glad the other posters are here and imparting their wisdom. It is really hard to be in your sitch because he is so out of line, however he holds (or thinks he does) all the power and so you can only look at and change your part in this. I say this because while we can focus all day on you (as that is all you can do), clearly this guy has some big issues.
I don't have a ton of advice because I am not sure there is much you can do right now. He is on the war path, and so all you can do is step back and protect yourself. I would not talk to him about D anymore or agree to any of his BS propositions. You are no dummy. Even if it feels to go against DB rules, protecting yourself and your finances always comes first. It is okay to tell him firmly "H, I am not willing to discuss this right now." You honestly don't owe him more explanation than that. You have already told him that you don't want D and are willing to work on the M, so he now knows, and there is no reason to repeat it--anything more will be perceived as pursuing and will serve to only push him away. As AS stated, when you "open the cage door" and they realize you won't stand in their way, sometimes they feel safe and back down a bit.
I am glad you are seeing an IC that you like. You need support right now! Please continue to take time for you, lean on your trusted family and friends, and work on those 180 and GAL. Sadly, these sitches can take a long, long time. Your H can try and expedite this and throw tantrums, but he is not above the law. Sounds like he has a pattern of bottling up anger, lashing out, and running, and so know that those patterns in him will repeat themselves until he is willing to do the work and take a long hard look at himself. That is not your circus--and not your monkeys--and you just do your best to push him to the side right now and keep your focus on you.
I think continuing to go dark and avoid future meetings is your best bet right now. Let him initiate all communication. And when he does, I think you should only give him a couple minutes of your time--listen, validate, and exit. He is not safe for you emotionally right now and appears to be a ticking time bomb or trying to manipulate you to get his way. I also think it is okay for him to worry you are moving right along without him, I wouldn't want him to think he can treat you this way and then just walk back into your life.
It is hard to switch the power dynamic when someone walks out on you, but it can be done! Hold your head up high, know your worth, and you keep treating yourself (and allow friends/family to) the way you deserve! This guy is acting like a big jerk and so I am glad you are not pining over him and I wouldn't want him to think that either.
Blu
“Forgiveness liberates the soul. It removes fear. That is why it is such a powerful weapon.” – Nelson Mandela